typedef struct Node {
    char data[100];  // 假设字符串最大长度为100
    struct Node* next;
} Lnode;

typedef struct Stack {
    struct Node* top;
    int size;
} Lstack;

void initializeStack(Lstack* stack);
int isEmpty(Lstack* stack) ;
int getSize(Lstack* stack);
void push(Lstack* stack, const char* value);
char* pop(Lstack* stack);
char* peek(Lstack* stack);
